libbpf: Add bpf_object pointer to kernel_supports().

Add a pointer to 'struct bpf_object' to kernel_supports() helper.
It will be used in the next patch.
No functional changes.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-13-alexei.starovoitov@gmail.com

tools/lib/bpf/libbpf.c

@@ -178,7 +178,7 @@ enum kern_feature_id {
 	__FEAT_CNT,
 };
 
-static bool kernel_supports(enum kern_feature_id feat_id);
+static bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id);
 
 enum reloc_type {
 	RELO_LD64,
@@ -2463,20 +2463,20 @@ static bool section_have_execinstr(struct bpf_object *obj, int idx)
 
 static bool btf_needs_sanitization(struct bpf_object *obj)
 {
-	bool has_func_global = kernel_supports(FEAT_BTF_GLOBAL_FUNC);
-	bool has_datasec = kernel_supports(FEAT_BTF_DATASEC);
-	bool has_float = kernel_supports(FEAT_BTF_FLOAT);
-	bool has_func = kernel_supports(FEAT_BTF_FUNC);
+	bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC);
+	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
+	bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
+	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
 
 	return !has_func || !has_datasec || !has_func_global || !has_float;
 }
 
 static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 {
-	bool has_func_global = kernel_supports(FEAT_BTF_GLOBAL_FUNC);
-	bool has_datasec = kernel_supports(FEAT_BTF_DATASEC);
-	bool has_float = kernel_supports(FEAT_BTF_FLOAT);
-	bool has_func = kernel_supports(FEAT_BTF_FUNC);
+	bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC);
+	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
+	bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
+	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
 	struct btf_type *t;
 	int i, j, vlen;
 
@@ -2682,7 +2682,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
 	if (!obj->btf)
 		return 0;
 
-	if (!kernel_supports(FEAT_BTF)) {
+	if (!kernel_supports(obj, FEAT_BTF)) {
 		if (kernel_needs_btf(obj)) {
 			err = -EOPNOTSUPP;
 			goto report;
@@ -4310,7 +4310,7 @@ static struct kern_feature_desc {
 	},
 };
 
-static bool kernel_supports(enum kern_feature_id feat_id)
+static bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
 {
 	struct kern_feature_desc *feat = &feature_probes[feat_id];
 	int ret;
@@ -4429,7 +4429,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map)
 
 	memset(&create_attr, 0, sizeof(create_attr));
 
-	if (kernel_supports(FEAT_PROG_NAME))
+	if (kernel_supports(obj, FEAT_PROG_NAME))
 		create_attr.name = map->name;
 	create_attr.map_ifindex = map->map_ifindex;
 	create_attr.map_type = def->type;
@@ -4994,7 +4994,7 @@ static int load_module_btfs(struct bpf_object *obj)
 	obj->btf_modules_loaded = true;
 
 	/* kernel too old to support module BTFs */
-	if (!kernel_supports(FEAT_MODULE_BTF))
+	if (!kernel_supports(obj, FEAT_MODULE_BTF))
 		return 0;
 
 	while (true) {
@@ -6518,7 +6518,7 @@ reloc_prog_func_and_line_info(const struct bpf_object *obj,
 	/* no .BTF.ext relocation if .BTF.ext is missing or kernel doesn't
 	 * supprot func/line info
 	 */
-	if (!obj->btf_ext || !kernel_supports(FEAT_BTF_FUNC))
+	if (!obj->btf_ext || !kernel_supports(obj, FEAT_BTF_FUNC))
 		return 0;
 
 	/* only attempt func info relocation if main program's func_info
@@ -7126,12 +7126,12 @@ static int bpf_object__sanitize_prog(struct bpf_object *obj, struct bpf_program
 		switch (func_id) {
 		case BPF_FUNC_probe_read_kernel:
 		case BPF_FUNC_probe_read_user:
-			if (!kernel_supports(FEAT_PROBE_READ_KERN))
+			if (!kernel_supports(obj, FEAT_PROBE_READ_KERN))
 				insn->imm = BPF_FUNC_probe_read;
 			break;
 		case BPF_FUNC_probe_read_kernel_str:
 		case BPF_FUNC_probe_read_user_str:
-			if (!kernel_supports(FEAT_PROBE_READ_KERN))
+			if (!kernel_supports(obj, FEAT_PROBE_READ_KERN))
 				insn->imm = BPF_FUNC_probe_read_str;
 			break;
 		default:
@@ -7166,12 +7166,12 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 
 	load_attr.prog_type = prog->type;
 	/* old kernels might not support specifying expected_attach_type */
-	if (!kernel_supports(FEAT_EXP_ATTACH_TYPE) && prog->sec_def &&
+	if (!kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE) && prog->sec_def &&
 	    prog->sec_def->is_exp_attach_type_optional)
 		load_attr.expected_attach_type = 0;
 	else
 		load_attr.expected_attach_type = prog->expected_attach_type;
-	if (kernel_supports(FEAT_PROG_NAME))
+	if (kernel_supports(prog->obj, FEAT_PROG_NAME))
 		load_attr.name = prog->name;
 	load_attr.insns = insns;
 	load_attr.insn_cnt = insns_cnt;
@@ -7187,7 +7187,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 
 	/* specify func_info/line_info only if kernel supports them */
 	btf_fd = bpf_object__btf_fd(prog->obj);
-	if (btf_fd >= 0 && kernel_supports(FEAT_BTF_FUNC)) {
+	if (btf_fd >= 0 && kernel_supports(prog->obj, FEAT_BTF_FUNC)) {
 		load_attr.prog_btf_fd = btf_fd;
 		load_attr.func_info = prog->func_info;
 		load_attr.func_info_rec_size = prog->func_info_rec_size;
@@ -7217,7 +7217,7 @@ retry_load:
 			pr_debug("verifier log:\n%s", log_buf);
 
 		if (prog->obj->rodata_map_idx >= 0 &&
-		    kernel_supports(FEAT_PROG_BIND_MAP)) {
+		    kernel_supports(prog->obj, FEAT_PROG_BIND_MAP)) {
 			struct bpf_map *rodata_map =
 				&prog->obj->maps[prog->obj->rodata_map_idx];
 
@@ -7575,11 +7575,11 @@ static int bpf_object__sanitize_maps(struct bpf_object *obj)
 	bpf_object__for_each_map(m, obj) {
 		if (!bpf_map__is_internal(m))
 			continue;
-		if (!kernel_supports(FEAT_GLOBAL_DATA)) {
+		if (!kernel_supports(obj, FEAT_GLOBAL_DATA)) {
 			pr_warn("kernel doesn't support global data\n");
 			return -ENOTSUP;
 		}
-		if (!kernel_supports(FEAT_ARRAY_MMAP))
+		if (!kernel_supports(obj, FEAT_ARRAY_MMAP))
 			m->def.map_flags ^= BPF_F_MMAPABLE;
 	}